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# Clinical Hold on Aardvark Trial Over Safety Issue
- URL: https://www.fdaweb.com/clinical-hold-on-aardvark-trial-over-safety-issue/
- Published: 2026-05-15T12:00:00.000Z
- Updated: 2026-09-14T13:39:22.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5161149

Aardvark Therapeutics said it plans to unblind key clinical trial data on its experimental metabolic drug ARD-101 after FDA imposed a full clinical hold on the program, affecting both its pivotal Phase 3 HERO study and an open-label extension trial. The hold reportedly followed reports of “reversible cardiac observations”" (specifically QRS prolongation) detected in healthy volunteers during a separate study, which showed potential for reduced heart efficiency at higher doses.

ARD-101 is being developed as a treatment for hyperphagia — an uncontrollable sensation of hunger — in patients with Prader-Willi syndrome, a rare genetic disorder associated with severe metabolic and behavioral complications.

In response to the regulatory action, the company said it will proceed with unblinding accumulated data from both the HERO trial and its extension study in order to assess the totality of efficacy and safety findings and help determine the program’s next steps.

The HERO trial (AVK-101-301) and its open-label extension enrolled patients with Prader-Willi syndrome, a population with few approved treatment options targeting hyperphagia. As of late February, the company had dosed 68 patients in the randomized trial and 19 patients in the extension study.

ARD-101 is described as an oral small-molecule drug designed to stimulate gut-peptide hormone release through activation of bitter taste receptors, a mechanism intended to regulate hunger signaling pathways.

The company has previously positioned ARD-101 as part of a broader metabolic disease pipeline focused on “hunger biology,” distinguishing hunger-driven neural pathways from appetite-related reward signaling.

Aardvark said it will continue engaging with FDA as it works to resolve the clinical hold and determine whether and how the program can advance.